}
Linear_interp z = new Linear_interp(x,y);
Ran myran = new Ran(17);
for (i=0;i<N;i++) {
xx[i]=(N-1)*myran.doub();
yy[i]=z.interp(xx[i]); // interpolated values
zz[i]=2.0*xx[i]; // Correct values
}
localflag = maxel(vecsub(zz,yy)) > sbeps;
globalflag = globalflag || localflag;
if (localflag) {